Dilution measurement and control at Lupin Operations, N.W.T.

CIM Bulletin, Vol. 87, No. 982, 1994

H..R. Bullis, R.A. Hureau and P.D. Soares, Lupin Operations, Echo Bay Mines Ltd., Nisku, Alberta

Echo Bay's Lupin Operation has produced more than 2.15 million ounces of gold since start-up in 1982. The mining method used to the present time has been longhole open stoping using trackless equipment. Because direct measurement of the open stopes has not been possible until recently, determining the exact qantity of unplanned dilution in previously mined stopes has not been possible. Estimates of dilution have been made using comparisons between production tons and grades against ore reserve tons and grades. This paper discusses tracking of grade and tonnage measurements from reserve estimation through production. Comparisons between estimated and actual tons and grade are presented, along with a brief description of methods used at the Lupin Operation to control dilution.